1. Technical Field
The invention concerns a facility for tying a door intercommunication system with a video camera to an integrated services digital network.
2. Discussion of Related Art
A method for automatically establishing a telephone connection from a door intercom station via a telephone set or a telephone installation is known from DE 4127316. To that end an activating switch is connected to a name key of the telephone set and to the door bell contact of the door intercom station. When a visitor activates the door bell contact, a telephone connection is automatically established to the number preprogrammed on the name key, e.g., the number of the office in which the occupant of the apartment works during the day. After the telephone connection is cleared, the door opener is activated by transmitting an audio frequency signal from the dialed call number. Due to the telephone link, the communication between the visitor and the occupant of the apartment is limited to verbal statements and identification. After the door opener has been activated no further verification by the occupant of the apartment is possible, e.g., whether the door was closed after the completion or the proper execution of an assignment, for example if the visitor is a mailman who wants to deliver a package to the apartment.